The most widely used natural sweetener, sugar, has problems associated with its use (especially causing weight gain by users). Many other sweeteners either have undesirable side effects or are deficient in certain respects. For example, aspartame loses its sweetness when exposed to elevated temperatures for long periods. This renders aspartame unsuitable for use in most baking applications.
Another problem is that existing artificial sweeteners have temporal sweetness profiles which do not exactly match that of sugar. For example, the sweetness may die out sooner. It may therefore be desirable to mix an existing artificial sweetener with another sweetener having a different temporal profile (so as to create a mixed sweetener that more closely matches the overall temporal sweetness profile of sugar).
Thus far, only relatively few sweet proteins (as distinguished from sweet carbohydrates) have been found in nature. See e.g. J. A. Morris et al., Biochem. Biophys. Acta. 261:114-122 (1972) (Monellin); H. Van Der Wel, FEBS Letters 21(1):88-90 (1972) (Thautmatin); D. Ming et al., Acta Botanica Yunnanica 8(2):181-192 (1986) (Mabinlin); and H. Yamashita et al., J. Bio. Chem. 265 (26):15770-15775 (1990) (Curculin). The disclosure of these articles and of all other articles referred to herein are incorporated by reference as if fully set forth herein. These sweet proteins are many times sweeter (for a given weight) than sugar, and are lower in calories.
The search for non-carbohydrate sweeteners has led to an examination of various plants which are known to be sweet. In H. van der Wel, et al., 14 Chemical Senses 75-79 (1989) the authors reported the existence of a sweet protein in Pentadiplandra brazzeana Baillon of about 12,000 Daltons per subunit that they named "Pentadin". This plant is a climbing shrub found in tropical Africa, especially in Gabon. It bears red globular berries of approximately five centimeters in diameter. Under their thick epicarp, these berries contain one to five reniform seeds surrounded by a thick soft layer of red pulp. The fruit used by these authors in their isolation attempt was a smoked and dried form of the plant. Unfortunately, attempts to isolate purer forms of Pentadin were unsuccessful.
As such, it can be seen that the need exists for an improved low calorie sweetener, especially one that is heat stable and has a different temporal sweetness profile from known artificial sweeteners.